Indonesia, especially the Kepulauan Riau, has very wide marine waters, and is rich in natural resources and marine biota diversity. One of the marine biota that has the potential to be developed is the marine sponge as an anti-inflammatory because it contains the flavonoid compound which is able to inhibit the cyclooxygenase enzyme that functions in the biosynthesis of prostaglandins. The purpose of this study was to determine whether marine sponge extract had anti-inflammatory activity against white male mice and to determine the optimal concentration of sea sponge extract gel was effective in inhibiting inflammationThe research method is experimental which uses carrageenan induction on the feet of mice. The thick extract of the marine sponge (Axinella carteri) will be formulated in the form of a gel with a concentration of 0.02%, 0.03%, 0.04% and a comparison (Voltaren emulgel) and a negative control in the form of (carbopol gel basis) gel. Parameters observed were inflammation caused by carrageenan and inhibition after treatment. Research data processing will be presented in the form of tables and graphs.This study showed that marine sponge extract gel preparations with a concentration of 0.02% to 0.04% had a healing effect on inflammation, and which had anti-inflammatory activity comparable to the positive control of Natrium diclofenac gel 1% is a marine sponge extract gel 0.04% with an inhibition percentage of 88.73%.The administration of marine sponge extract gel (Axinella carteri) gave a positive response to reducing the size of the leg edema of mice. From the percentage of inhibition that was calculated and the effective gel concentration was 0.04% because it had relatively the same effectiveness as the percentage of inhibition of the positive control. This can be used as a new alternative that utilizes natural ingredients, especially those from Natuna Regency, Riau Islands in the treatment of inflammation with fewer side effects.